Environmentally compatible processes compositions and materials treated thereby

ABSTRACT

An environmentally friendly process for treating crops, especially sweet potatoes, to prevent or at least inhibit deterioration of the edible plant matter, involves contacting the plant matter with an aqueous composition including phosphonic acid, also known as phosphorous acid, together with at least one of citric acid, phosphoric acid and sulfuric acid, preferably at least phosphoric acid, sufficient to lower the treating water to a pH of less than 4, and also containing at least one of the metals or metal ions of silver, copper and zinc in an amount of 1 to 1,000 ppm. The composition may optionally also contain hydrogen peroxide.

RELATED APPLICATIONS

This is a continuation of U.S. patent application Ser. No. 11/636,534,filed Dec. 11, 2006, which is a divisional continuation-in-part of U.S.Pat. No. 7,147,872, issued Dec. 12, 2006 (application Ser. No.11/202,197, filed Aug. 12, 2005), itself a division of U.S. Pat. No.6,946,155, issued Sep. 29, 2005 (application Ser. No. 10/792,759, filedMar. 5, 2004), which is a division of U.S. Pat. No. 6,797,302, issuedSep. 28, 2004, (application Ser. No. 09/744,681, filed Jan. 29, 2001),which application was the U.S. national stage application under 35 USC§371 of International Application No. PCT/IL99/00403, filed Jul. 22,1999, the entire contents of each of which are hereby incorporated byreference, and claiming priority of Israeli Application No. 125,520filed Jul. 27, 1998.

FIELD OF THE INVENTION

The present invention concerns environmentally friendly processes andcompositions for preventing qualitative deterioration and quantitativeloss of plant matter and foodstuffs, during all stages of storage andhandling, including pre and post harvest, pre and post planting,distribution and marketing, as well as for preventing sprouting, rootingand promoting fecundity of certain plant matter. The processes andcompositions of the present invention can also be used to reduce andeliminate harmful organisms and substances from earth, other growthmedia and substrates, equipment, materials, water, spaces and surfaces.

BACKGROUND OF THE INVENTION

The present invention involves processes and compositions utilizingprimarily aqueous hydrogen peroxide for preventing qualitative andquantitative loss of foodstuffs and plant matter during storage and/orhandling of such foodstuffs and plant matter. The present invention alsoinvolves a process for effecting Epical Dominance Breakdown in certainplant propagation material and as a consequence achieving a number ofnotable benefits, including storage stability of the plant propagationmaterial itself and higher product yields, when such material isplanted. The processes and compositions of the present invention canalso be used to reduce and eliminate harmful organisms and substancesfrom earth, other growth media and substrates, equipment, materials,water, spaces and surfaces.

Hydrogen peroxide itself is an environmentally friendly material becauseits decomposition products are water and oxygen. Its use in the presentinvention in optional combination with other components is limited tosuch compositions and processes that are environmentally friendly,either because the other components are in themselves environmentallyfriendly or they are used in quantities that do not constitute a dangerto individuals or to the environment.

Deteriorative losses of foodstuffs and plant matter during growing,storage and handling is a high priority global problem of considerablesocial, economic and political importance. Quantitative and qualitativelosses during all stages of foodstuff and plant matter growing, storageand handling, impacts first and foremost on the possibility to sustain areasonable nutritional level and life quality for the earth'sinhabitants. Consequently, processes and compositions that cancontribute significantly to quantitative and qualitative loss preventionare of paramount importance. The present invention concerns effectiveprocesses and compositions for such purposes. What is more, the presentinvention concerns environmentally friendly and energy conservingprocesses and compositions for such ends.

The process and compositions of the invention inhibits plant matter,such as potatoes, seeds and foodstuffs from sprouting, rooting andpathogenic attack and decay, so that such material can be stored underconditions of high relative humidity (70-99+%), optimized to preventweight loss by dehydration, during storage, for even extended periods oftime. The process and compositions of the invention also allow storageunder conditions of relatively high temperatures, i.e., low degree ofrefrigeration, in combination with high relative humidity. Thisfacilitates significant energy savings relative to lower temperaturerefrigeration, usually required for foodstuff and plant matter storage,particularly under conditions of high relative humidity.

These factors are of prime importance in the post harvest period. Butthey are also significant in all stages of foodstuff and plant mattergrowing, storage and handling.

In the event of extended storage period it can be advantageous to treatthe stored plant matter or foodstuff every few weeks with the inhibitingsolution and according to the process of the invention. In addition, inthe interim period between such treatments, the stored plant matter orfoodstuff can be maintained in an aseptic environment by providing alower level dosage on a more frequent or regular basis, by solutions andtreatments that provide the aseptic environment in conjunction with theadditional humidity. The process of the invention is readily adaptableto be implemented during transit of the treated matter. This is ofconsiderable significance since agricultural products, particularly foodproducts, are produced by and large only during limited seasons of theyear. In order for such food products to be available for human andanimal consumption during all or at least extended seasons of the year,they must be stored under conditions that minimize losses bydehydration, pathogenic decay, sprouting, rooting and the like, whilemaintaining organoleptic qualities and preventing other processes thatadversely affect their quality.

It is also of the utmost importance that methods and materials employedin extending the effective storage lifetime of perishable foodstuffs andplant matter, should not be detrimental to the consumers' personalhealth and welfare, nor cause any harm to the environment. While onespecific application of the present invention so far has been to extendthe effective storage quality and lifetime of potatoes, it is selfevident that the same or similar processes and materials can be used toextend the effective storage quality and lifetime, increase crop yieldsand specifically increase crop yields on a commercial scale, of plantmaterial and foodstuffs in general. This applies not only to similarvegetable food crops, such as, sweet potatoes, carrots, onions,radishes, garlic, etc., but the process and compositions of theinvention can be used to good advantage to extend the storage qualityand lifetime of potato seeds, sweet potato propagation material, as wellas bulbs, including flower bulbs and tubers. The present invention canalso be suited to inhibit sprouting in seeds and grains. Furthermore,the process of the invention imparts extended shelf life stability, toall sorts of foodstuffs and plant material, including fruits andvegetables, so treated.

A reference that deals at length with the specific topic of potatoes asan example, and some of its related problems is; Smith, O., POTATOES:Production, Storing, Processing, The Avi Publishing Co., Inc., Westport,Conn.

The current total global yield of potatoes is estimated to be in thevicinity of 300 million tons per annum. It is both a basic food staplebecause of its inherent nutritional value, being rich in carbohydratesand other nutrients, and at the same time is frequently prepared forquick snacks as French fries or chips. It is even used in gourmetdishes, wherein product quality, taste and texture are more critical.Since the conditions under which potatoes grow, prevail only in certainseasons of the year in the various regions of the globe in which theyare grown, the issue of preventing qualitative and quantitative lossesduring storage or during inter regional trade, is vital to thoseinvolved with potato growing, storage, trade and consumption.Dehydration during storage is one of the major reasons for weight lossin absolute quantitative terms. At the same time, it contributes toqualitative deterioration in the potatoes themselves. The amount ofweight lost by dehydration during storage is determined by thecharacteristics of the specific potato varieties involved and by thestorage regime. An environment with high relative humidity preventswater loss by evaporation from stored potatoes. Whereas an environmentwith low relative humidity can take up a substantial amount of moisturefrom stored potatoes. Water loss by dehydration of stored potatoes isweight loss of the stored product and consequently a direct economicloss.

Moreover, water losses from stored potatoes can adversely affect theirquality in other ways. Tubers that have lost significant quantities ofwater by dehydration are softer than tubers that have been stored underconditions that reduce or prevent such water losses. They are also moresubject to bruising and consequently more vulnerable to pathogenicattack and decay.

To prevent weight loss due to dehydration, potatoes are normally storedunder conditions of high relative humidity. Such conditions, unlesscertain counter measures are invoked, are known to promote sprouting androoting of the stored potatoes, undesirable processes that contribute tothe deterioration in potato quality and sometimes even total loss of thepotatoes. In addition, high humidity environment frequently favors thegrowth of pathogens that both contribute to and promote qualitative andquantitative losses.

The materials in use up to now to prevent such undesirable consequencesof storage include isopropylphenylcarbamate (IPC), chloroisopropylphenylcarbamate (CIPC) (see for example, Hajslova, J., andDavidek, J., 1986, Sprout inhibitors IPC and CIPC in treated potatoes,Nahrung Food, 30, 75-79), maleic hydrazide (see for example, Yada, R.Y., Coffin, R. H., Keenan, M. K., Fitts, M., Duffault, C. and Tai G. C.C., 1991, Effect of maleic hydrazide on potato yield, sugar content andchip color etc., Amer. Potato J., 68, 705-709),1,2-dihydro-3,6-pyridazinedione and 2,3,5,6,-tetrachloronitrobenzene(TCNB).

Use of CIPC is the most widespread practical method today of keepingpotatoes sprout-free during storage. However, the use of this sproutinhibitor creates a number of problems. These include suppression ofsuberization and periderm formation, requiring as a consequence specialadditional treatment after the curing process. Moreover, CIPC leavestoxic residues on the tubers to which it is applied. The ambient storagetemperature required to inhibit sprouting during potato storage is 2-4°C. Maintaining this relatively low temperature requires significantenergy expenditure and cost. There is also a tendency for starches to beconverted to sugars at temperatures below 9° C. and thereby degrade thetaste characteristics of the potatoes, particularly potatoes intendedfor industry. Such potatoes therefore suffer from lower consumeracceptability while for some industrial application such potatoes aretotally unacceptable. Moreover, CIPC has to be volatilized at relativelyhigh temperatures (170°-180° C.) before introduction into the storagechamber, thereby effecting an undesirable burden on the refrigerationsystem and an extra expenditure of energy.

For potatoes harvested during the normal potato harvest season, twooptions are available to prevent sprouting and rooting. One involvesmaintaining storage temperatures between 2 and 4° C. The other allowsstorage at higher temperatures, but requires treatment with CIPC andother chemicals that inhibit sprouting. In the case of late harvestpotatoes, storage at temperatures even as low as 2 to 4° C., does notprovide assurance of effective sprouting inhibition. In such cases, evensupplemental treatment with CIPC does not assure effective sproutinginhibition. On the other hand, the process of the present invention doesprovide effective sprouting and rooting inhibition over a widetemperature range.

While the usual storage temperatures employed with CIPC treatment arewithin the range 7 to 8° C., the process of the invention has been foundto impart effective sprouting and rooting inhibition over a wide rangeof temperatures. This includes the current relevant range of storagefrom 2 to 10° C. It also includes a wide range of ambient temperatures.It should be emphasized once more that the possibility of allowinghigher storage temperature provides a way of achieving substantialenergy savings with economic, qualitative, quantitative and ecologicalbenefits. Furthermore, certain embodiments of the present inventionfacilitate adjustment of the carbon dioxide-oxygen gas balance in thestorage rooms, thus preventing “black-heart” deterioration in the storedpotatoes. CIPC and similar based treatment processes do not inherentlyinvolve such gas balance adjustments.

It should be pointed out that CIPC is not effective at temperatures of5° C. and below. In various circumstances, such as late harvest,sprouting can occur at such temperatures. However, the process andcompositions of the present invention are effective in inhibitingsprouting, even at temperatures of 5° C. and below. Experiments haveshown that the interval between successive treatments for effectivecontrol by the process and compositions of the present invention can beprolonged to as long as two to six months, under these conditions.

The wide temperature range that is suitable for storing plant matter andfoodstuffs treated by the process and compositions of the presentinvention also provides greater flexibility to accommodate a relativelywide variety of different conditions encountered in various facilitiesand environments. The process of the invention can also be implementedwhile the plant matter or foodstuff is being transported, thus providinga means for inhibiting deteriorative processes in transit, and alsoconserving time.

CIPC has a number of additional deficiencies that the process of thepresent invention overcomes. CIPC is systemic to tubers, fruits andfoodstuffs treated with it. That is to say it penetrates into the bulkof such tubers, fruits and foodstuffs. As a consequence, this results ina number of limitations that include:

(1) regulations that prohibit use of CIPC, to treat certain foodmaterials;

(2) potatoes and similar foodstuffs that been treated with CIPC mustundergo a waiting period of at least a month or two before they aremarketed, in order to allow the CIPC to decompose;

(3) a storage room or bin in which CIPC treatment took place, isprohibited from being used for food or seed storage;

(4) application of CIPC requires special equipment that is expensive toacquire and maintain, a high and specific temperature to transform theliquid into a gas, and constant supervision of a skilled technicianduring the entire period of operation;

(5) CIPC attacks plastic, leaves a black, difficult to remove layer onthe surface of the storage room and leaves active residues in the wallsfor a period of years;

(6) CIPC has to be volatilized at high temperatures before introductioninto storage chambers, thereby adversely affecting the temperaturebalance therein.

All the above-mentioned disadvantages of CIPC are eliminated when theprocess of the present invention is used instead of CIPC treatment. Thisis because the decomposition products of the compounds used in thepresent invention are harmless. For the most part, they consist of waterand oxygen, with merely trace, practically undetectable quantities ofother optional components, when used. In certain embodiments, it alsoprovides for carbon dioxide-oxygen gas balance adjustment, therebyinhibiting “black-heart” deterioration of stored potatoes.

Finally, in certain countries the use of CIPC is either restricted or inthe process of being restricted and even prohibited. The other materialsmentioned above, aside from those of the present invention, do notconstitute attractive alternatives to the use of CIPC, because ofsimilar or other deficiencies.

Hydrogen peroxide is a well-known non-polluting oxidizing agent. Acomprehensive article summarizing its production, uses and otherfeatures is presented in Kirk-Othmer, Encyclopedia of ChemicalTechnology, 4th Edition, Vol. 13, pages 961-995. The said article andits bibliography are incorporated herein by reference. The known usesfor hydrogen peroxide described in the Kirk-Othmer article include watertreatment, disinfection and sterilization of contact surfaces of foodpackaging. The use of hydrogen peroxide for space decontamination wasalso indicated as holding promise. The bibliography also cites variouspatents that involve stabilized hydrogen peroxide compositions. Such acomposition containing silver salt or complex is described in WO96/18301, while U.S. Pat. No. 4,915,955 concerns a stabilized silversalt compound or colloid for mixing with hydrogen peroxide to produceeffective disinfectants. No mention is made in the article concerningthe use of hydrogen peroxide or its compositions for treating foodstuffsor plant material.

The use of hydrogen peroxide in combination with silver ions fordisinfection of water is also described in Shuval, H., et al, Water Sci.Technol., (1995), 31(5-6, Health-Related Water Microbiology 1994),123-9, and in Shuval, H., et al, Water Supply, (1995), 13(2 IWSAInternational Specialized Conference on Disinfection of Potable Water,1994), 241-51.

While occasional and sporadic reports in technical and sales promotionalliterature and meetings have indicated that hydrogen peroxide treatmentcan be beneficial for foodstuff and plant matter conservation, a recentsummary presented at a meeting of the European Association for PotatoResearch that took place on Mar. 25-29, 1998, at Aberdeen, Scotland,indicated that such treatments are less effective than availablealternatives. See, for example, Clayton, R. C., and Black, S., POTATOSEED STORE HYGIENE: CLEANING, DISINFECTION OR BOTH? Presentation atmeeting of European Association for Potato Research, Mar. 25-29, 1998,at Aberdeen, Scotland.

Among publications that one might note as indicating possible benefitsfrom hydrogen peroxide treatment of foodstuffs and plant matter, one cancite the following:

Afek, A., et al, NEW APPROACHES FOR INHIBITION OF SPROUTING ANDREDUCTION OF WEIGHT LOSS DURING POTATO STORAGE, Abstracts of ConferencePapers, Posters and Demonstrations, 13th Triennial Conference of theEuropean Association for Potato Research, July 14-19, VeldhovenNetherlands and Postharvest, Taupo, New Zealand, August, 1996. Thispublication describes an ultrasonic technique for treating potatoes instorage with a solution containing 25% ethanol and 0.3% of a commercialconcentrate containing hydrogen peroxide and silver ion. While theefficiency of the treatment in sprout inhibition was reported to becomparable to the standard CIPC treatment, no indication was given ofeffectiveness of treatment with aqueous hydrogen peroxide without theethanol.

A sales promotion brochure for a preparation with the name Virosil-Agroclaims that the preparation is effective in preventing post-harvestdeterioration in a large variety of fruits and vegetables. Thepreparation itself is described as “a multi-component complexformulation containing hydrogen peroxide and silver in cationic form.”The forms of application do not include “Dry Fog”.

In an article in Hebrew by Nir, A. and Heller, D., in HaSadeh, Vol. 74,No. 12, pp. 1326-7, mixed results are reported for the disinfection ofhatching eggs with a hydrogen peroxide preparation applied with anultra-sonic fogger. No explanation is provided for the lack ofconsistency in results, although good results were reported for the morerecent series of tests.

The mixed and inconclusive results observed so far for application ofpreparations containing hydrogen peroxide to foodstuffs and plants canprobably be rationalized as follows:

Hydrogen peroxide is a strong oxidizing agent. It is also a strongdisinfectant, effectively eliminating or at least reducing a widevariety of pathogens, including pathogens that cause decay. Beinghowever at the same time a strong oxidizing agent, it can also causedamage surface tissues and protective peels and coatings of foodstuffsand plant matter, thereby making them more vulnerable to pathogenpenetration. Consequently, reluctance so far to adopt environmentallyfriendly, hydrogen peroxide based processes and compositions fortreating foodstuffs and plant matter to prevent qualitative andquantitative losses during storage and handling, can be attributed to alarge extent to the absence of reliable processes and compositions forthis purpose, that provide consistently effective results.

Consequently, it is an object of certain aspects of the presentinvention to provide a process and/or hydrogen peroxide containingcompositions that allows plant matter and foodstuffs to be stored underconditions of high relative humidity and high relative temperature,while inhibiting detrimental processes that cause deterioration inquality that are frequently promoted by conditions of high relativehumidity and temperature. Thus it is possible to gain the variousbenefits of high humidity and temperature storage without incurringdetrimental consequences, frequently effected by storage of foodstuffsin a high humidity and high relative temperature ambiance. Thesprouting, rooting and “black-heart” formation of potatoes or similartubers during storage can be cited as examples of detrimental processesthat occurs during storage, particularly in a high humidity and highrelative temperature ambiance.

It is also an object of certain aspects of the present invention toprovide a treatment process and/or compositions that prevent sprouting,rooting and “black-heart” formation of potatoes, other tubers, bulbs,seeds, grains, onions and other food and plant propagation material,particularly under conditions of high humidity and relatively hightemperature storage. The said process also allows for convenientadjustment of carbon dioxide-oxygen gas balance, thereby inhibiting“black-heart” deterioration in potatoes.

It is also an object of certain aspects of the present invention toprovide a process and/or compositions that result in energy savingsduring storage and handling of foodstuffs and plant matter.

It is also an object of certain aspects of the process of the presentinvention to apply a treatment process and/or compositions on seeds andplant propagation material that reduce losses from harvest until sowing,inhibit sprouting, protect seeds without loss of water necessary forgrowth, allow seeds to be maintained in an aseptic condition, so thatthey do not transmit infections and diseases, from country to country,to neighboring seeds, to the harvests they will produce or the earth inwhich they are planted.

It is another object of certain aspects of the present invention toprovide processes and/or compositions that effect and promote EpicalDominance Breakdown, thereby inhibiting premature undesirable sproutingbut ultimately promoting enhanced sprouting capability and in additionpromoting and enhancing part of or all the following benefits andadvantages in appropriate plant matter, e.g. in potatoes:

(1) more stems per tuber relative to an untreated control;

(2) greener and richer foliage;

(3) more uniform growth height;

(4) more tubers per maternal tuber;

(5) higher yields in kg/square meter;

(6) greater uniformity in the size distribution of the harvest product,particularly in standard sizes for industry, for marketing and forseeds;

(7) the pre-treatment in accordance with process and compositions of theinvention preserves the maternal tuber from deteriorative processes thatwould ultimately contaminate the yields, and

(8) because the effects of the treatment on seeds is beneficial, totalflexibility is provided to the storers of potatoes to market his produceto industry or/and consumer markets and/or for seed, all in accordancewith market conditions. This can be done immediately after treatmentwithout having to wait a month as required after treatment with CIPC.

The treatment process and/or compositions provided by the invention aretotal substitutes to the treatment and compositions in use at presentfor seed matter before export and/or before actual sowing. Furthermore,it is friendly to man and the environment, simple and economical toimplement. The most common material in use until recently and still inuse in some countries for this purpose is ethyl methyl mercury chloride.This material contains a high concentration of organic mercury and hastherefore been prohibited for use in most of the countries of the world.This is because it is dangerous to the health of the user, and containsa toxic metal that contaminates the ground and aquifers.

The new treatment process and/or compositions of the present inventionare more efficient. They possess additional beneficial and superiorproperties. They are friendly to the user and the environment, incomparison to other alternative seed treatments with various sorts offungicides and fumigation with formaldehyde.

It is an additional object of certain aspects of the present inventionto provide a process and/or compositions for preventing modes ofqualitative and/or quantitative losses of potatoes during storage, forexample by decay caused by infection with microorganisms, fungi, algae,yeasts, molds and viruses.

It is yet another purpose of certain aspects of the present invention toprovide a storage process for storage of plant matter and foodstuffsthat prevents qualitative and quantitative losses during storage, byundesirable microbiological or biochemical processes of the foodstuffitself, including when such processes are effected and/or promoted byhigh humidity and high temperature storage conditions.

It is also an object of certain aspects of the present invention toprovide processes and compositions that can be used to reduce andeliminate harmful organisms and substances from earth, equipmentmaterials, spaces and surfaces.

Moreover, it is an important object of certain aspects of the presentinvention to achieve the above purposes in a simple way, that is safe touse, non-toxic, odorless, without hazardous residues and/or sideeffects, compatible with the environment and that does not leave anyundesirable chemical residues in the materials or water, earth, othergrowth media and substrates, or on equipment, materials, water, spacesand surfaces exposed to the treatment by the process and compositions ofthe present invention, or endanger the health of operators implementingthe process or handling the compositions or the foodstuffs treated bythem. The process and compositions of the present invention are costeffective.

SUMMARY OF THE INVENTION

Percentages throughout the specification indicate weight-by-weightpercentages.

In accordance with a preferred embodiment of the present invention,there is provided an environmentally compatible process for treatingplant matter and foodstuffs, during storage, distribution and marketing,preplanting, growing, and pre and/or post harvest, to increase yields,eliminate health hazards, impart storage stability, extend shelf lifeand inhibit premature sprouting, rooting, germination, blossoming,decay, “black-heart” formation, pathogenic losses and other processescausing losses in quality and/or quantity of said plant matter andfoodstuffs, said plant matter and foodstuffs including tubers—such aspotatoes, bulbs, seeds grains and other germinating matter or items,plant vegetative propagation matter or items, as well as various fruitsand vegetables including solanaceous fruits and vegetables, by treatingthe said plant matter or foodstuffs, during storage and/or distributionand marketing, pre-planting and/or during pre and/or post harvest withan effective aqueous dosage comprising an effective concentration ofhydrogen peroxide and optionally comprising, an effective dosage of oneor more additional components selected from the following types ofsubstances:

(i) effective-trace concentrations of dispersed metals or metal ions;

(ii) effective concentrations of other and/or additional hydrogenperoxide activators, synergists and promoters;

(iii) effective concentrations of hydrogen peroxide stabilizers andmodifiers;

(iv) effective concentrations of pH regulators;

(v) effective concentrations of organic and/or inorganic additives,

wherein the effective concentration of hydrogen peroxide, time oftreatment and form of application are such as to prevent such plantmatter and foodstuffs quality and/or quantity loss, but at the same timenot so high as to cause or induce damage to the plant matter andfoodstuffs themselves.

In accordance with another preferred embodiment of the presentinvention, there is provided a process for preventing prematuresprouting and enhancing the productivity in plant growth material, e.g.,potatoes, potato tubers, potato growth material or other plant growthmaterial, by effecting Epical Dominance Breakdown in the said potatoes,potato tubers, potato growth material or other plant growth material,comprising treating the potatoes, potato tubers, potato growth materialor other plant growth material with an effective aqueous dosagecomprising an effective concentration of hydrogen peroxide andoptionally comprising, one or more additional components selected fromthe following types of substances:

(i) effective trace concentrations of dispersed metals or metal ions;

(ii) effective concentrations of other and/or additional hydrogenperoxide activators, synergists and promoters;

(iii) effective concentrations of hydrogen peroxide stabilizers andmodifiers;

(iv) effective concentrations of pH regulators;

(v) effective concentrations of organic and/or inorganic additives.

In accordance with another preferred embodiment of the presentinvention, there is provided a composition for treating in anenvironmental friendly manner, plant matter and foodstuffs, duringstorage, distribution and marketing, pre-planting, growing, and preand/or post harvest, to increase yields, eliminate health hazards,impart storage stability, extend shelf life and inhibit prematuresprouting, rooting, “black-heart” formation, germination, blossoming,decay, pathogenic losses and other processes causing losses in qualityand/or quantity of said plant matter and foodstuffs, and promote epicaldominance breakdown, said plant matter and foodstuffs includingtubers—such as potatoes, bulbs, seeds grains and other germinatingmatter or items, plant vegetative propagation matter or items, as wellas various fruits and vegetables including solanaceous fruits andvegetables, said composition being also suitable to treat earth, othergrowth media and substrates, equipment, materials, water, spaces andsurfaces to reduce and eliminate harmful organisms and substancestherefrom, comprising

(a) 0.001% to 50% of hydrogen peroxide

(c) 0.001% to 5% of metal ion selected from the group consisting ofcopper, zinc, nickel, iron, manganese, molybdenum, potassium orcombinations thereof

and optionally

(i) effective trace concentrations of other dispersed metals or metalions;

(ii) effective concentrations of other and/or additional hydrogenperoxide activators, synergists and promoters;

(iii) effective concentrations of hydrogen peroxide stabilizers andmodifiers;

(iv) effective concentrations of pH regulators;

(v) effective concentrations of organic and/or inorganic additives.

In accordance with yet another preferred embodiment of the presentinvention, there is provided a composition for treating in anenvironmental friendly manner, plant matter and foodstuffs, duringstorage, distribution and marketing, pre-planting, growing, and preand/or post harvest, to increase yields, eliminate health hazards,impart storage stability, extend shelf life and inhibit prematuresprouting, rooting, “black-heart” formation, germination, blossoming,decay, pathogenic losses and other processes causing losses in qualityand/or quantity of said plant matter and foodstuffs, and promote epicaldominance breakdown, said plant matter and foodstuffs includingtubers—such as potatoes, bulbs, seeds grains and other germinatingmatter or items, plant vegetative propagation matter or items, as wellas various fruits and vegetables including solanaceous fruits andvegetables, said composition being also suitable to treat earth, othergrowth media and substrates, equipment, materials, water, spaces andsurfaces to reduce and eliminate harmful organisms and substancestherefrom, comprising

(a) 0.001% to 50% of hydrogen peroxide

(b) 0.001% to 2.5% of silver ion

(c) 0.001% to 2.5% of metal ion selected from the group consisting ofcopper, zinc, nickel, iron, manganese, molybdenum, potassium orcombinations thereof

and optionally

(i) effective trace concentrations of other dispersed metals or metalions;

(ii) effective concentrations of other and/or additional hydrogenperoxide activators, synergists and promoters;

(iii) effective concentrations of hydrogen peroxide stabilizers andmodifiers;

(iv) effective concentrations of pH regulators;

v) effective concentrations of organic and/or inorganic additives.

In yet another embodiment of the invention, there is provided anenvironmentally compatible process for reducing and eliminating harmfulorganisms and substances from earth, equipment, materials, water, spacesand surfaces by treating the said earth, other growth media andsubstrates, equipment, materials, water, spaces and surfaces with aneffective dosage of a composition comprising an effective concentrationof hydrogen peroxide and optionally comprising, an effective dosage ofone or more additional components selected from the following types ofsubstances:

(i) effective trace concentrations of dispersed metals or metal ions;

(ii) effective concentrations of other and/or additional hydrogenperoxide activators, synergists and promoters;

(iii) effective concentrations of hydrogen peroxide stabilizers andmodifiers;

(iv) effective concentrations of pH regulators;

(v) effective concentrations of organic and/or inorganic additives.

DETAILED DESCRIPTION OF THE INVENTION

The preferred range of concentrations or hydrogen peroxide for use inintermittent treatment of foodstuff and plant matter in accordance withthe process of the present invention is from 0.001% to 50%, preferablyfrom 0.01% to 20% and more specifically from 0.1% to 15%. The preferredrange of concentrations for continuous or short interval treatment is 10PPM to 40%.

The range of concentrations of dispersed metal and/or metal ion for usein accordance with this invention is from 1 PPB to 5%, preferably from10 PPB to 10,000 PPM, more specifically from 20 PPB to 2000 PPM and evenmore specifically from 20 PPB to 1000 PPM. The combination of hydrogenperoxide with appropriate metal ion(s) provides in certain instances asynergistic effect by which the hydrogen peroxide effect is enhanced. Inaddition, the minute trace residue quantities of the metal ion(s) havebeen found to have a slower but longer lasting beneficial effect on theprevention of quality and quantity deterioration of foodstuff and plantmatter.

The treatment of the treated matter in accordance with this inventioncan be implemented satisfactorily in various ways. These include, incertain cases dipping the treated matter in the above-mentionedsolution(s) or spraying the solution(s) onto the treated foodstuff orplant matter. However it should be pointed out that water or condensedwater droplets on the surface of foodstuff and plant matter can enhancethe proliferation of pathogens and thus have a detrimental effect. Thisis of particularly concern when it is important to maintain storageconditions of high relative humidity, such as in the storage of potatoesto prevent material loss due to evaporation and other forms ofdeterioration induced by a low humidity environment.

Intermittent treatment by means of the process and compositions of thepresent invention protects foodstuff and plant matter so treated fromadverse effects of condensation of water on the surfaces of thefoodstuffs and plant matter, so treated.

The application of the solution in the form of ultra small drops bysolution atomizing systems that produce “dry” fogs with particle sizesof less than and up to 1000 microns in diameter, has been found toprovide particularly beneficial results. These include compensation foror prevention of water loss, inhibition of sprouting, rot inhibition,less overall losses and higher yields for treated seeds. The beneficialresults include epical dominance breakdown. The advantages of smallparticle size “dry” fog is attributed to the fact that very smallparticles behave to a large extent like a gas. They facilitate theachievement of very high relative humidity, i.e., even as high as 99%+,without any condensation on the stored matter. Furthermore, the smallparticles show a very high penetrability into small cracks and spaces.As a consequence, even when potatoes are stored in ordinary stacks orstorage sacks, the “dry” fog storage has a high degree of penetrabilityand accessibility to all points in the stack or sack. This means thateven in the simplest and most space compact facilities stored plantmatter, such as potatoes and similar items, can he effectively treatedto prevent weight loss due to dehydration as well as softening and otherdeteriorative processes brought about by an inadequate humidityenvironment.

Another benefit of the “dry” fog is that it allows higher concentrationsof hydrogen peroxide and other active ingredients to be used withoutcausing damage to the protective peel or surface of the plant matter sotreated. The higher concentration of treating solutions enhances theireffectiveness in the rapid elimination of pathogens. When the foodstuffand plant matter is treated by dipping or ordinary spraying, the optimalhydrogen peroxide concentration should be substantially between0.5%-1.5% and treating time between a few seconds up to a few minutes.When the treatment is applied as a “dry” fog, the hydrogen peroxideconcentration may be up to 40% and the time of application from severalhours to a number of days.

A further benefit of application by fog is that it allows for convenientadjustment of the carbon dioxide-oxygen balance in the storage room orchamber, thus inhibiting “black heart” deterioration. Preferably, theair to liquid volume ratio in the fog should be between 300:1 and1200:1, more preferably between 500:1 and 700:1.

In certain aspects and applications, the beneficial effects of theprocess of the present invention are enhanced by the addition of certainadditives to the treatment solution, these additives may include:

Stabilizers and modifiers, such as but not limited to citric acid,tartaric acid, boric acid, bromic acid, stannates, phosphonic acids,etc.

pH regulators, primarily mineral and organic acids, such as but notlimited to phosphoric acid, peracetic acid, hydrochloric acid, sulfuricacid, etc. For optimum effectiveness, the pH should be lower than 6 andpreferably between 1 and 4.

Trace element activators, synergists and promoters, such as but notlimited to dispersions of metal, non-metals or ions (of various valenceswhen appropriate) such as, copper, zinc, nickel, iron, potassium,manganese, silver, chromium, molybdenum, magnesium, boron, phosphorus,iodine, sulfur, citrate, etc.

Organic or inorganic additives, such as but not limited to peraceticacid, phenol, gelatin, glycerin, sodium azide, polymoxin B, sodiumbicarbonate, pectin, salicylic acid, etc.

EXAMPLES Example 1

In several experiments conducted in a storage room containing hundredsof metric tons of potatoes, a hydrogen peroxide-metal ion solution wasintroduced with a fogger overnight until a relative humidity level of80-99% was attained. The potatoes were kept in the storage room for 5months, during which time fogging treatment was effected 10-50% of thetime. The result of the spraying was that losses due to disease werereduced from 8% to 2%, while losses due to dehydration were reduced from5% to 2%. Therefore the total loss reduction was from 13% to 4.5%, a netaverage reclamation of 8.5%.

Example 2

The effect of treatment with various solutions of aqueous hydrogenperoxide plus additives at the following concentrations: 0% (control)and 0.1%-30%, by dipping for various lengths of time. Clear-cut sproutinhibition was obtained for bulbs so treated, compared to the control,as well as decay prevention for extended time.

In certain concentrations, an opposite result was obtained, of rot andsevere phytotoxic damage to the tubers.

Each of the treatments were repeated five times. Each time involved 50kilograms of potatoes.

Example 3

Same as Example 2, except that instead of dipping, the solutions weresprayed onto the foodstuff substrate until dripping (high volume).

Example 4

Same as Example 3, except that the spraying onto the foodstuff substratewas low volume.

Example 5

Same as Example 3, except that the spraying onto the foodstuff substratewas ultra low volume.

Example 6

Same as Example 3, except that the spraying onto the foodstuff substratewas by fogging. The gas liquid volume ratio was 600:1.

Examples 7-11

Each of the treatments described in examples 2-6 above were carried outon potato seeds.

Examples 12-16

Each of the treatments described in examples 2-6 above were carried outon wheat seeds, corn (maize), various grains and solanaceous plants. Theconcentrations of the hydrogen peroxide solutions were varied between0.1-60%. The species so treated were examined after periods of 7-10days. In all cases, no sprouting, blossoming and germination wereobserved.

The same species were examined after varying periods of several weeks toseveral months. Inhibition of decay was observed.

In certain concentrations, an opposite result was obtained, of rot andsevere phytotoxic damage to the tubers.

Example 17

750 tons of potatoes of the Desiree variety were stored in each of threecold rooms for six months at 10° C. At an average relative humidity of97% provided as 3-7 micron droplets, weight loss after this time wasonly 2.8%. With a regular humidifier and average relative humidity of92%, the weight loss was 6%. The weight loss in the control, averagehumidity 85%, was 11%.

In addition, the quality of potatoes stored without providing humiditywas low because of softening. The firmness of the different batches ofpotatoes described above were as follows: 64 newtons for 97% relativehumidity; 58 newtons for 92% relative humidity and 48 newtons for 85%relative humidity. Potato firmness before storage was 70 newtons.

Example 18

Experiments were conducted to test the effectiveness of treating potatoseeds to prevent sprouting, with a “dry” fog comprising, hydrogenperoxide, silver ion and phosphoric acid. After preliminary treatmentwith the active solution, the storage conditions were maintained at 90%relative humidity and 10° C. The results were as follows:

Concentration (PPM) Sprouting (%) H₂0₂ Ag ion one month two months threemonths 0 0 15 27 35 500 1 4 23 31 1,250 2.5 0 3 6 5,000 10 0 2 5

By repeating the above dosage on a monthly basis, it was possible tototally eliminate sprouting for extended periods. However at levelsabove 25% H₂O₂, damage was caused to the peel that developed rapidly torot.

Example 19

Experiments were conducted to test the effectiveness of treating potatoseeds to prevent sprouting, with a “dry” fog containing hydrogenperoxide and silver ion. After preliminary treatment with the activesolution, the storage conditions were maintained at 90% relativehumidity and 10° C. The results were as follows:

Concentration (PPM) Sprouting (%) H₂O₂ Ag ion Cu ion one month twomonths three months 0 0 0 15 27 35 500 0 0 8 22 32 500 1 0 4 23 31 500 01 6 17 27 500 0.1 0.9 2 13 18

By repeating the above dosage on a monthly basis, it was possible tototally eliminate sprouting for extended periods. However at levelsabove 25% H₂O₂, damage was caused to the peel that developed rapidly torot.

Example 20

Experiments were conducted to test the effect on yield enhancement oftreating potato seeds with solutions containing hydrogen peroxide andsilver ion. The potato seeds were initially harvested in late June andput into cold storage at 9-10° C. and 96-99+% RH, initially untreated.Approximately one month later, each batch of various potato seedvarieties was treated with a dose of a solution containing hydrogenperoxide and silver ion, the ratio of the active ingredients to thepotato seeds being 2-5% H₂O₂ and 40-100 PPM Ag ion on a wt/wt basis.Each batch was treated three more times. The second treatment took placeabout three and one half weeks after the first treatment and was at thesame dosage level. The third treatment was almost four weeks after thesecond treatment but the dosage level was reduced by half. The fourthtreatment was about three weeks later also at the half dosage level.

The average potato yields in kilogram/square-meter for various potatoseed varieties, were as follows:

Treated Potatoes Untreated Potatoes After 84 days, 2.28 kg/m² 1.65 kg/m²After 94 days, 2.56 kg/m² 2.04 kg/m²

In addition to the higher yields in weight per unit area, the potatoesthat were produced from treated potato seeds had a more uniform sizedistribution as well as a higher yield of marketable sizes relative tothose of the untreated control. In addition, the maternal tubersremained robust and did not deteriorate so that the crop was notcontaminated. The problem of maternal tuber deterioration and cropcontamination is a basic problem of untreated potato seeds.

General Examples

The following is a number of additional examples of applications of thepresent new invention in various areas requiring humid and asepticconditions:

(1) Treatment of hot-house plants and growth products;

(2) Treatment related to growing and marketing of mushrooms and buds;

(3) Treatment in meat storage;

(4) Treatment of eggs for eating or incubation for increasing moistureand preventing infection;

(5) Treatment of incubation spaces, incubation cells and hatching cells.

(6) Treatment of space and equipment in surgical operation rooms;

(7) Treatment of space and equipment in crowded halls and enclosedareas, such as, subway stations, buses, airplanes, ships and the like;

(8) Various treatments of sown earth to prevent ground pollution,instead of methyl bromide whose use is being prohibited.

(9) Storage spaces, greenhouses, hen houses, etc.

In the treatment of water, it is desirable to augment the compositionwith ethanol, and/or to augment the beneficial pathogen-killing effectof the composition further by heating the water and/or by illuminatingthe water treated with the present composition with infrared (IR)radiation and/or ultraviolet (UV) radiation.

Such radiation can be applied either immediately before or immediatelyafter treating the water with the aforementioned composition. When bothIR and UV are administered they can be administered sequentially or atthe same time. When administered sequentially, the IR radiation can beadministered first or alternatively the UV radiation can be administeredfirst, all in accordance with the present invention.

For the treatment of water, it has been found to be beneficial to alsosubject the water, either immediately before treatment with the hydrogenperoxide solution or immediately thereafter, or simultaneouslytherewith, to Infra Red and/or Ultra Violet radiation. Ultravioletradiation is at a wavelength of less than 400 nm whereas infraredradiation is at a wavelength of greater than 700 nm. In accordance withthe present invention, when UV and/or IR is/are used, selectedwavelengths are preferred.

Any wavelength of Infra Red or Ultra Violet will provide someimprovement, but the best is achieved by using an Infra Red radiation inthe near Infra Red range, the wavelength of 0.75-1.4 μm being the best,and a wavelength of 1.4-3.0 μm being second best, and/or an Ultra Violetwavelength of less than 280 nm. The quantity of hydrogen peroxidesolution according to the present invention can be reduced by use of IRand/or UV.

The composition of the present invention remains stable at relativelyhigh temperatures, even as great as 90-95° C. Therefore, the presentcomposition can be used in the treatment of water even at such hightemperatures. It will be understood that heating water alone often willnot kill all pathogens, e.g. the Legionnaires disease pathogens whichsurvive in hot water systems. Thus, the composition of the presentinvention is effective in the treatment not only of relatively coolwater systems, e.g. swimming pools, but also in warm and hot waterenvironments, e.g. hot tubs or the like, where water temperatures mayexceed 30 or even 35° C., as well as in hot water heating systems wherethe temperatures may reach as high as 95° C. or even more. Indeed, withhot water systems the effectiveness of the present composition doubleswith every 20° C. increase in temperature, up until about 95° C.

It has been indicated above that dispersed metals or metal ions usefulin the present invention include copper, zinc, nickel, iron, potassium,magnate, chromium, molybdenum, manganese and boron, as well as silverand compounds or ions of phosphorous, iodine, sulfur and citrate. Inaddition to those, ions and/or fine particles of titanium and lithiummay also be included. Also, in addition to the acids mentioned above,nitric acid may also be included.

While certain embodiments of the invention have been hereinbeforeparticularly described, it will be apparent to anyone skilled in the artthat many modifications and variations may be made, that do not deviatefrom the main features or spirit of the invention. The invention isaccordingly not to be construed as restricted to such embodiments, butrather to its concept, spirit and general scope.

1. A method of treating edible plant matter to inhibit deteriorationthereof by undesirable microbiological or biochemical processes duringstorage and handling of the edible plant matter, comprising contactingthe edible plant matter with an aqueous composition by at least one ofdipping the edible plant matter in the aqueous composition, spraying theaqueous composition onto the edible plant matter and exposing the ediblematter to a fog of the aqueous composition, wherein the aqueouscomposition has a pH no greater than 4 and comprises (1) phosphonicacid, (2) metals or metallic ions of at least one of silver, copper andzinc, present in the aqueous composition in an amount of 1 ppm to 1,000ppm, and (3) at least one of citric acid, phosphoric acid and sulfuricacid.
 2. The method of claim 1 wherein the edible matter comprises sweetpotatoes.
 3. The method of claim 2, wherein the metal or metal ionsconsist essentially of silver.
 4. The method of claim 2, wherein theacids, other than the phosphonic acid, are at least one of phosphoricacid and citric acid.
 5. A method of killing pathogens in water,comprising adding to said water an amount sufficient of a hydrogenperoxide solution having a pH of less than 4, to kill pathogens in saidwater, wherein said hydrogen peroxide solution contains metallic ions ofsilver, copper and zinc, said metallic ions being present in saidhydrogen peroxide solution in an amount of 10 ppb to 5%; wherein saidhydrogen peroxide solution contains peracetic, sulfuric, phosphonic,salicylic, citric and phosphoric acids, and wherein said solution alsocontains glycerin.